Extreme pressure lubricant and extreme pressure agents therefor



Patented Feb. 20, 1951 EXTREME PRESSURE LUBRICANT AND EX? TREME PRESSUREAGENTS THEREFOR Charles A. Weisel, Somerville, and Elmer B. Cyphers,Cranford, N. 1., asslgnors to Standard Oil Development Company, acorporation of Delaware No Drawing. Application December 1, 1948, SerialNo. 62.981

This invention relates to extreme pressure lubricants and particularlyto lubricating compositions which h'ave extreme pressure propertiesimparted to them by the addition of the reaction products of chlorinatedhydrocarbons with phosphorus sulfides, halides or oxides.

It has been known in the prior art that chlorinated organic compounds ofvarious types have certain load-carrying properties when added tolubricating oils. For example, it is known that chlorinated phenol, suchas pentachlorphenol, when added to mineral oil compositions, increasesfilm strength and wear-resisting properties.

The present invention is based on the discovery that materials of thisgeneral type may be further improved I in the properties mentioned bymodifying the molecular structure to incorporate phosphorus therein. Awide variety of phosphate esters containing the pentachlorphenyl radicalmay be obtained for this purpose. For example,.

pentachlorphenol may be reacted with P001: in the presence of pyridineto form a reaction product containing phosphorus which has good filmstrength and wearresisting properties. This reaction proceeds accordingto the following typical equation:

301 011-!- P]; (CsChOhPO 31101 The product of the above reactionpossesses low solubility in mineral oil. By including an alcohol in thereaction mixture, the solubility is improved, the reaction proceedingaccording to the following equation:

=CaCl5 R=alkyl, alkenyl, alicyclic radical, or halogenated radicalPyridine 1 011 212011 Pool, (0)(R0);P0 3HCl Pyridine 245011 IROH Pooh0), R0)P0 3HCl 5 Claims. (01. 252-493) It is understood that any .of theabove products may be present. 'Some (ROhPO may also be presentin theproduct. The predominant or major product is dependent on the quantitiesof materials used.

Instead of using POCh, a phosphorus sulfide may be used, for example,phosphorus pentasulfide. In this case, the reaction may be typified bythe following equations:

In the reaction of pentachlorphenol with the phosphorus sulfides, thereaction products may possess limited solubility in oil. Byincorporating an aliphatic alcohol ROH where R is an alkyl, alkenyl,alicyclic or halogenated radical, as may be done in the reaction withP0013 described above, the solubility is increased. If such an alcoholis incorporated into the molecule, a mixture of products will beobtained which will include s wohi sn, (aoxami sn and possibly some(ROhl SH where and R represent the aforementioned radicals. Bycontrolling the amounts of reactants used, a product havingpredominantly the structure of one of the above equations may beobtained.

The above materials may also possess fungicidal and insecticidalproperties.

The thiophosphate ester described above contains an acidic group whichwill react to form metal or NH4 salts. Salts of Ba, C Sr, Mg, Al and Cu+are especially preferred as additives for lubricating oils. The metalsalts produced according to this reaction appear to be valuable also asdetergents and have value also as insecticides and fungicides.

The metal salts, especially those of alkali metals such as sodium, willreact with various halides to form the complete ester. These reactionsare illustrated in the following equation:

wherein Me is metal or ammonium, X is halogen, and R is an alkyl,alkenyl, or alicyclic hydrocarbon or halogenated hydrocarbon radical.

The above equations are exemplary, but it will be understood that theinvention is not limited in any way to the specific examples cited. Forexample, alkyl, alkenyl, or alicyclic substituted tetrachlorphenols andtheir derivatives may be used in lieu of pentachlorphenol with the samebeneficial results.

In addition to various oxygen-containing prod- 3 ucts which may beobtained as above, related products may be obtained by using othercompounds of phosphorus, sulfur and chlorine in lieu of POCla and P285.Thus, PSCh may obviously be substituted for P0012, P2520: may besubstituted for P235, and other phosphorus sul-.

fides and/or phosphorus sulfide-oxides may be used to prepare compoundswhich contain both oxygen and sulfur. The following types of compoundsare contemplated as being within the scope of the invention.

It will be noted that the left portion of the molecule, including P, iscommon to all these structures. The following general formula typifiesthe invention more broadly:

RO/ \YZ Example A mixed phosphate ester was prepared by using-2 mols ofC; oxo alcohol and 1 mol of pentachlorphenol. To a mixture consisting of107 grams of pentachlorphenol, 104 grams Ca oxo alcohol, 96 grams ofpyridine, 350 ml. benzene, and 200 ml. toluene chilled to 5 0., therewas added dropwise over a period of about three hours 61.8 grams ofphosphorus oxychloride (POClJ) During the period while the POCb wasbeing added, the temperature of the solution was ermitted to rise to C.to facilitate solution of the pentachlorphenol. It was found necessaryto add more benzene, about 100 ml., to keep the pyridine hydrochloridemixture fluid.

The foregoing mixture was permitted to stand overnight at roomtemperature and thereafter the mixture was refluxed for five hours andthe solid material removed by filtration. The filtrate was washed withwater and was dried over potassium carbonate and calcium chloride. Thesolvent and excess Ca oxo alcohol were then removed by heating to 165 C.at a reduced pressure of mm. The residual material weighed 170 grams. 27grams of pentachlorphenol was recovered from the pyridine hydrochloride.

The residual product described above was analyzed and found to contain4.96% phosphorus and 29.24% chlorine by weight. Calculated on a; basisof the theoretical phosphorus content would be 5.43% and the chlorinecontent 31.1% which was in reasonably close agreement.

The oxo alcohol employed in this example was prepared from a C7 olefincut obtained from the polymerization of olefins by phosphoric acidcatalysis, by means of the 0x0 reaction of the olefin with carbonmonoxide and hydrogen.

A 2% blend of the complex phosphate product having the theoreticalformula just given, was prepared in a phenol extracted coastal stocklubricating oil of about 45 SSU viscosity at 210 F. This'blend wasevaluated in the standard Almen machine and in the Shell 4-Ball ExtremePressure Tester. The data obtained, in comparison with the base stockand two standard commercial additives. are shown in the following table:

Table 1 Shell 4-Ball E. P. Tester 20 Load, 30 min. Operation Wear ScarDiameter. mm. avcmgo of 2 Runs Almcn Machine Gradual Loading Wei htsCarried Lubricant PlelmolFExt. Coastal Stock 45 seal Phosphate +2%Commercial Oilincss Agent (Fattv ester) 2% Commercial Oiliness Agent('lncresyl Phosphate) Table II S L E. Timken Machine chine Lbs. Carriedat 1000 R. P. M.

Concentration of Additive in Mineral Oil San Width Percent From theforegoing data, it is apparent that the phosphate prepared from 2 mclsof C8 oxo alcohol and 1 mol of pentachlorphenol is a particularly usefuladditive both under conditions of extreme pressure and under conditionswhere the applied load is more moderate. The complex phosphate possesseshigh load-carrying capacity as demonstrated by the excellent valuesobtained on the Almen, the S. A. E. and the Timken machines. The Shell4-Ball test also indicates that the complex phosphate is very eiiectivein decreasing wear. Numerous additives in the prior art have shownsuperior results on one or two of these tests, but it is consideredexceptional to find a product which demonstrates excellent properties onall of them.

In addition to the excellent pressure properties set forth above, theproduct of the present invention may be varied slightly to produce anexcellent rust inhibitor as well as to retain good film strengthproperties. Such a. product also is None " 1,5 useful for dispersingsludge in lubricating oil.

110a, le -O a, RS0,0

In each of the above formulas, R represents an alkyl or alkylsubstituted aromatic group having anefiective chain length of at least 6carbon atoms in order to ensure oil solubility. The preferred chainlength is from about 7 or 8 to 20 or more carbon atoms. Among thalcohols which may be employed are n-hexyl, z-ethylhexyl, syntheticalcohols prepared from C0 and hydrogen or from olefins, CO and hydrogenby means of the oxo reaction, dodecyl, octadecyl, oleyl, and mixtures ofthese and similar alcohols such as those derived by the hydrogenation ofcocoanut oil and other natural fatty oil acids. The symbol in the aboveformulas represents the chlorinated hydrocarbon portion of a phenol, forexample, the pentachlorphenyl group.

As previously mentioned, the active chlorinated organic group need notbe limitedto pentachlorphenol since various related materials may besubstituted for this ingredient. Thus, various tetrachlorphenols andsubstituted chlorinated )henols such as chlorinated cresols and relatedilkylated derivatives of chlorinated phenols, for xample, chlorinatedisopropyl or tertiary butyl lhenol or carvacrol, and the like, may beemlloyed in lieu of pentachlorphenol. Compounds raving the majorproportion of chlorine attached 0 the ring are preferred by reason oftheir greater ;tability and less corrosive tendency.

When products ofthe type Just described are used as minor constituentsin mineral oils, such as crankcase lubricants and the like, theyincrease film strength to some degree and are particularly useful indispersing sludge and preventing the formation of rust. Hence, they areuseful additives for crankcase oils used in airplane engines or in anyoperation where conditions of high humidity and high temperature areencountered.

The modifying agent of the present invention may be used in variousproportions and in various types of oils. Their utility is not limitedto mineral base lubricating oils but they may be employed also insynthetic oils such as those incorporating the esters of polybasicacids, polyglycols and the like. In the following claims, the expressionoil, when not otherwise restricted, will be understood as referringgenerically to the synthetic oils as well as those of petroleum origin.

In general, useful quantities of the additive may vary from as little as0.1 to as much as 20% by weight, based on the total composition.Proportions of 0.1 to are preferred where oiliness is the preferredcharacteristic. Where extreme pressure lubrication is' the paramountobject. the proportions may be as high as 20% of additive. In case it isdesired to market concentrates, the contact of additive may beconsiderably higher. The additives are useful in various grades of oilfrom the lightest lubricating grades about 35 SSU at 210 F.) to those ofhigh viscosity such as 1000 SSU at 210 F. They may also be used ingreases and mixtures of mineral base and synthetic base oils,emulsifiable oils, and the like. Other conventional additives such as 6anti-oxidants, rust inhibitors, viscosity index improvers, pourpountdepressors, and the like, may be employed, as will be obvious to thoseskilled in the art.

What is claimed is:

1. A composition of matter havingthe general formula where R is an alkylgroup of at least 6 and not more than 20 carbon atoms and is apentachlorphenol radical.

2. A lubricating composition comprising to 99.9% by weight of alubricating'oil selected from the class which consists of mineral baseoil and synthetic oils of polybasic acid ester and polyglycol type and0.1 to 20% of a material having the general formula wherein R is analkyl group of at least 6 and not more than 20 carbon atoms and 4s is apentachlorphenol radical.

3. A lubricating oil consisting essentially of a mineral base oil of 35to 1000 SSU viscosity at 210 F. containing 0.1 to 20% by weight of acomposition having the general formula where R is an alkyl group of atleast 6 and not more than 20 carbon atoms and c is a pentachlorphenolradical.

4. A lubricating oil containing 0.1 to 20% by weight, based on the totalcomposition, of a material having the general formula where R is analkyl group of at least a and not tHn t h CHARLESAWE'ISEL.EIAIERECYPHERS.

REFERENCES CITED Q The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2.033.916 Bass Mar. 17, 19302,223,329 Moyle Nov. 28, 1940 2.242 260 Prutton May 20, 1941 2,279,218Badertscher Apr. 7, 1942

3. A LUBRICATING OIL CONSISTING ESSENTIALLY OF A MINERAL BASE OIL OF 35TO 1000 SSU VISCOSITY AT 210* F. CONTAINING 0.1 TO 20% BY WEIGHT OF ACOMPOSITION HAVING THE GENERAL FORMULA